feat(frontend): T44 setup FastAPI static files and templates

- Mount static files on /static endpoint
- Configure Jinja2Templates with directory structure
- Create base template with Pico.css, HTMX, Chart.js
- Create all template subdirectories (auth, dashboard, keys, tokens, profile, components)
- Create initial CSS and JS files
- Add tests for static files and templates configuration

Tests: 12 passing
Coverage: 100% on new configuration code

templates/auth/register.html

@@ -0,0 +1,64 @@
+{% extends "base.html" %}
+
+{% block title %}Register - OpenRouter Monitor{% endblock %}
+
+{% block content %}
+<article class="grid">
+    <div>
+        <h1>Create Account</h1>
+        <p>Register to start monitoring your OpenRouter API keys.</p>
+    </div>
+    <div>
+        <form action="/register" method="POST" hx-post="/register" hx-swap="outerHTML" hx-target="this">
+            {% if error %}
+            <div class="alert alert-danger" role="alert">
+                {{ error }}
+            </div>
+            {% endif %}
+            
+            <label for="email">
+                Email
+                <input type="email" id="email" name="email" placeholder="your@email.com" required>
+            </label>
+            
+            <label for="password">
+                Password
+                <input 
+                    type="password" 
+                    id="password" 
+                    name="password" 
+                    placeholder="Password" 
+                    required 
+                    minlength="8"
+                    pattern="^(?=.*[a-z])(?=.*[A-Z])(?=.*\d).+$"
+                    title="Password must contain at least one lowercase letter, one uppercase letter, and one number"
+                >
+                <small>Minimum 8 characters with uppercase, lowercase, and number</small>
+            </label>
+            
+            <label for="password_confirm">
+                Confirm Password
+                <input type="password" id="password_confirm" name="password_confirm" placeholder="Confirm password" required>
+            </label>
+            
+            <button type="submit">Register</button>
+        </form>
+        
+        <p>Already have an account? <a href="/login">Login here</a>.</p>
+    </div>
+</article>
+
+<script>
+// Client-side password match validation
+document.getElementById('password_confirm').addEventListener('input', function() {
+    const password = document.getElementById('password').value;
+    const confirm = this.value;
+    
+    if (password !== confirm) {
+        this.setCustomValidity('Passwords do not match');
+    } else {
+        this.setCustomValidity('');
+    }
+});
+</script>
+{% endblock %}